Analysis of texture and connected-component contours for the automatic identification of writers

Recent advances in "off-line" writer identification allow for new applications in handwritten text retrieval from archives of scanned historical documents. This paper describes new algorithms for forensic or historical writer identification, using the contours of fragmented connected-components in free-style handwriting. The writer is considered to be characterized by a stochastic pattern generator, producing a family of character fragments (fraglets). Using a codebook of such fraglets from an independent training set, the probability distribution of fraglet contours was computed for an independent test set. Results revealed a high sensitivity of the fraglet histogram in identifying individual writers on the basis of a paragraph of text. Large-scale experiments on the optimal size of Kohonen maps of fraglet contours were performed, showing usable classification rates within a non-critical range of Kohonen map dimensions. The proposed automatic approach bridges the gap between image-statistics approaches and purely knowledge-based manual character-based methods

Design of a fractional control using performance contours. Application to an electromechanical system

The article proposes a frequency-based method to design a controller ensuring dynamic behavior of a closed-loop control: the first overshoot of the step response in the tracking mode or in the regulation mode, the damping ratio and the natural frequency of its dominant oscillatory mode. This method uses two contours called “performance contours” and constructed on the Nichols diagram. The first contour is the common Nichols magnitude contour which can be considered as an iso-overshoot contour. The second contour, whose construction and analytic expression are given in this article, is a new contour defined on the Nichols diagram and parameterized by the damping ratio. The proposed method uses complex non-integer (or fractional) differentiation to compute a transfer function whose open-loop Nichols locus tangents both performance contours, thus ensuring stability margins (or stability degree). The method is applied to a DC motor whose speed is controlled

Removing micromelody from fundamental frequency contours

In this paper we describe a new method to diminish microprosodic components of fundamental frequency contours by applying weight functions linked to microprosodically classified phone combinations. For vowel segments in obstruent environments our algorithm outperforms standard smoothing algorithms like Moving-Average filtering, Savitzky-Golay filtering or MOMEL in diminishing F0 variations related to microprosodic factors while retaining significant differences related to macroprosody

Effects of non-Hermitian perturbations on Weyl Hamiltonians with arbitrary topological charges

We provide a systematic study of non-Hermitian topologically charged systems. Starting from a Hermitian Hamiltonian supporting Weyl points with arbitrary topological charge, adding a non-Hermitian perturbation transforms the Weyl points to one-dimensional exceptional contours. We analytical prove that the topological charge is preserved on the exceptional contours. In contrast to Hermitian systems, the addition of gain and loss allows for a new class of topological phase transition: when two oppositely charged exceptional contours touch, the topological charge can dissipate without opening a gap. These effects can be demonstrated in realistic photonics and acoustics systems.Comment: 11 pages, 9 figure

Making a Public Difference in the Ministry of Word and Witness

(Excerpt) Today, the liberating movement of faith and a new cycle of societal change coincide to bring our churches and North American society itself to a turning point. The ecclesial and social situation alike call for a new era of ministry to make a public difference. My presentation will focus on the ethical contours of faithful community empowered by the living Word, and some public dimensions of parish ministry that responds to the Word through social witness